Addison's Disease Secondary to Bilateral Adrenal Gland Metastatic Mammary Carcinoma in a Dog.

A 12 yr old intact female Siberian husky was referred with a 2 wk history of progressive weakness, paraparesis, anorexia, and panting. A 4 cm diameter grade 3 mammary solid carcinoma involving the fifth right mammary gland had been removed 2 days prior to the current visit. While hospitalized, the dog was diagnosed with Addison's disease based on electrolyte disturbances and low serum cortisol levels following adrenocorticotropic hormone stimulation test. An abdominal ultrasound revealed adrenal glands at the upper limit of normal size. Despite treatment, the dog deteriorated and died 4 days after presentation. A postmortem examination revealed a neoplastic infiltrate of epithelial malignant cells in both adrenal glands, popliteal lymph nodes, vertebral bodies, and paralumbar musculature, compatible with metastasis from mammary carcinoma. To our knowledge, this is the first reported case of Addison's disease secondary to metastatic mammary carcinoma in a dog.

Successful Treatment of 3 Dogs With Fluoroquinolone-Resistant Escherichia coli Associated Granulomatous Colitis.

Successful resolution of Escherichia coli associated granulomatous colitis (ECGC) is becoming a challenge due to the development of fluoroquinolone resistant E coli, which is associated with poor prognosis. Three dogs presented with signs of chronic colitis and were diagnosed with ECGC. All 3 were initially treated with enrofloxacin and trimethoprim-sulfamethoxazole, without clinical improvement. Despite the fact that culture and susceptibility testing results demonstrate resistance to fluoroquinolone and trimethoprim-sulfamethoxazole, the addition of amikacin fully resolved the clinical signs in all 3 cases. This case series describes the clinical presentation, diagnostic findings, and successful treatment of 3 dogs with fluoroquinolone-resistant ECGC. It suggests an alternative strategy for multidrug-resistance ECGC patients. Further investigations are required to confirm the efficacy of and to determine the molecular mechanisms underpinning the apparent success of aminoglycoside antibiotic combinations for treatment of ECGC.